{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lecture4 - Chem 120a Spring 07 Dirac Notation Bras and Kets...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chem 120a Dirac Notation: Bras and Kets 01/24/07 Spring 07 Lecture 4 Reading: Feynman Chapter 1 and 3.1, 3.2 Last time, talked about quantum behaviors: P = | φ | 2 (1) (a) If 2 paths, φ = φ 1 + φ 2 , which plugging into (1) gives interference patterns (b) Along each path, φ = j j φ (c) if measure which path is taken, lose interference P = | φ 1 | 2 + | φ 2 | 2 Analyzing the decomposition of paths, we have: φ (y) = ii i1 , 2 ˆ ys s T|s s s = i , ˆ sT | s , i ss are all numbers representing probability amplitudes Æ this is an idealized analysis: we are assuming no medium, that is, nothing happens to the electron as it travels from the source s to the slit and then from the slit to the detector y. Æ if there is a medium, represent it with a generic operator ˆ Θ , i.e. i ˆ y| s Θ Nevertheless, in the ideal case, we have i ˆ | s i = T i = T = 1 and φ (y) = T , 2 = We have the completeness relation , 2 ss = = 1 φ (y) = 1 y , 2 = s = ys YAHOO!
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Bra-Kets in detail ab and ˆ a| b Θ are probability amplitudes s is a fundamental item called a ket It is a vector in complex vector space. ‘Physically’, it describes the state of the system we’re looking at
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 3

lecture4 - Chem 120a Spring 07 Dirac Notation Bras and Kets...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon bookmark
Ask a homework question - tutors are online